1. Field of the Invention
The present invention relates to a check valve with a spherical closing member arranged in a flow duct of a valve body. The spherical closing member is displaceable by the medium flowing through the valve and in a closing position rests against a sealing portion with an elastic sealing member. The spherical closing member is guided by guide ribs which are arranged in the flow duct and include stop surfaces.
2. Description of the Related Art
Check valves of the above-described type are known, for example, from a brochure of Georg Fischer AG "Kugelruckschlagventil" [Ball Check Valve], Brochure No. FI 679M of March 1984.
The known check valve mentioned above has the disadvantage that when the check valve is opened, a large cross-sectional flow area is immediately created, so that in case of greater flow velocity of the medium, turbulences and vibrations occur which cause the spherical closing member to be pushed back and forth. This results in wear and breaks of the material of the closing member, so that over a long period of time, a problem-free sealing effect in the closed position cannot be ensured. Wear also occurs at the stop surfaces and the guide ribs for the closing member. The worn or broken material components cause impurities in the medium and may lead to additional damage in valves, pumps and other fittings arranged in the pipe line system.